Veins are thin-walled and contain one-way valves that control blood flow. Normally, the valves open to allow blood to flow into the deeper veins and close to prevent back-flow into the superficial veins. When the valves are malfunctioning or only partially functioning, however, they no longer prevent the back-flow of blood into the superficial veins. As a result, venous pressure builds at the site of the faulty valves. Because the veins are thin walled and not able to withstand the increased pressure, they become what are known as varicose veins which are veins that are dilated, tortuous or engorged.
In particular, varicose veins of the lower extremities is one of the most common medical conditions of the adult population. It is estimated that varicose veins affect approximately 40% of adult females and 25% of males. Symptoms include discomfort, aching of the legs, itching, cosmetic deformities, and swelling. If left untreated, varicose veins may cause medical complications such as bleeding, phlebitis, ulcerations, thrombi and lipodermatosclerosis.
Traditional treatments for varicosities include both temporary and permanent techniques. Temporary treatments involve use of compression stockings and elevation of the diseased extremities. While providing temporary relief of symptoms, these techniques do not correct the underlying cause, that is the faulty valves. Permanent treatments include surgical excision of the diseased segments, ambulatory phlebectomy, and occlusion of the vein through chemical or thermal means.
Surgical excision requires general anesthesia and a long recovery period. Even with its high clinical success rate, surgical excision is rapidly becoming an outmoded technique due to the high costs of treatment and complication risks from surgery. Ambulatory phlebectomy involves avulsion of the varicose vein segment using multiple stab incisions through the skin. The procedure is done on an outpatient basis, but is still relatively expensive due to the length of time required to perform the procedure.
Chemical occlusion, also known as sclerotherapy, is an in-office procedure involving the injection of an irritant chemical into the vein. The chemical acts upon the inner lining of the vein walls causing them to occlude and block blood flow. Although a popular treatment option, complications can be severe including skin ulceration, anaphylactic reactions and permanent skin staining. Treatment is limited to veins of a particular size range. In addition, there is a relatively high recurrence rate due to vessel recanalization.
Endovascular ablation therapy is another alternative treatment technique for venous reflux diseases. Common forms of energy used to ablate and treat varicose veins include laser or RF energy. For this type of treatment, the energy is delivered by an elongated energy delivering member, such as an optical fiber or RF probe, that is percutaneously inserted into the diseased vein prior to energy delivery. An introducer catheter or sheath may first be inserted and advanced to within a few centimeters of the saphenous-femoral junction of the greater saphenous vein. Once the introducer catheter is properly positioned, elongated energy delivering member is inserted into the lumen of the catheter or sheath and advanced until elongated energy delivering member is in place at the treatment site. Next, tumescent anesthesia is injected several times along the diseased vein segment. The tumescent injections can be used to perform several functions. The anesthesia inhibits pain caused from the application of thermal energy to the vein. The tumescent injection also provides a barrier between the vessel and the adjacent tissue and nerve structures, which restricts radiant heat damage to within the vessel and prevents non-target tissue damage. The tumescent injection also compresses the vein by reducing its diameter which increases the success of the procedure.
The use of tumescent anesthesia may lead to several problems. The first problem with tumescent anesthesia is it's often the longest procedural step in the treatment, usually requiring two medical professionals to perform. Depending on vein length and location, the administration of tumescent anesthesia may take up to 15 minutes or more. Multiple tumescent anesthesia injections are often required along substantially the entire length of the target vein segment. Another problem with the delivery of tumescent anesthesia is that the multiple “needle-stick” injections can be painful and cause discomfort to the patient. These “needle-stick” injections may scar, and can lead to complications, such as inadvertent needle contact with non-targeted structures, such as nerves, or lead to possible infection. In addition, the needle-sticks can be difficult to control, and the vein is sometimes perforated which enhances bruising. Also, the tumescent anesthesia sometimes insufficiently surrounds the vein and pain and parasthesia can result. An object of this invention is to provide a treatment for varicose veins without requiring the use of tumescent anesthesia.
Plasma, often referred to as the fourth state of matter, is defined as a specific state of matter of electrically charged particles, consisting of, but not limited to, ions, charged molecules, electrons, sub-atomic particles, and excited atoms. Plasma is generally regarded by scientists and those skilled in the art as a separate state of matter different from gas, liquid, or solid.
Non-thermal plasma is a form of plasma existing at low temperatures, such as room temperature, is defined when electrons achieve the energy level normally found in all components of thermal plasma. Non-thermal plasma produced by this invention may be of a temperature below the pain threshold of the surrounding tissue which is roughly between about 45-50° C., and this non-thermal plasma temperature is well below that of current energy-based treatment methods, such as laser which sometimes exceed over 1000° C. immediately adjacent to the fiber emitting tip.
Recently, non-thermal or low-thermal plasmas have been used by those in the art for various procedures. Such non-thermal or low-thermal plasmas are also sometimes called cold plasma or non-equilibrium plasma. Uses of non-thermal plasmas in the art include sterilization of foodstuffs and treatment of topical skin surfaces of patients. An object of this invention is to use either thermal plasma or non-thermal plasma in a novel way for the treatment of hollow anatomical structures within the body.